John K. Chan

Molecular Profiling and Tumor Biomarker Analysis of GOG281/LOGS: A Positive Late-Phase Trial of Trametinib for Recurrent/Persistent Low-Grade Serous Ovarian Carcinoma

Abstract Purpose: Low-grade serous ovarian carcinoma (LGSOC) is a distinct form of ovarian cancer characterized by younger patient age and relative chemoresistance. The GOG281/LOGS trial (NCT02101788) investigated the efficacy of the MEK inhibitor trametinib compared with physician’s choice standard-of-care (SOC) in patients with LGSOC with persistent/recurrent disease. The study demonstrated significantly improved progression-free survival (PFS) in the trametinib-treated arm. Experimental Design: Two hundred and sixty patients with recurrent/persistent LGSOC were enrolled and randomly assigned in GOG281. We performed molecular analysis of 170 patients with available tumor specimens, comprising whole-exome sequencing and phospho-ERK (pERK) IHC, to identify biomarkers of clinical benefit from trametinib. The demographics of the translational cohort (n = 170) were comparable with those of the total trial cohort. Results: High tumor pERK expression (greater than the median histoscore of 140) was associated with significantly prolonged PFS with trametinib treatment versus SOC (median 20.1 vs. 5.6 months, log-rank P < 0.0001; test for interaction P = 0.023). Tumors harboring canonical RAS–RAF–MAPK mutations (KRAS/BRAF/NRAS: 44/134, 32.8% of cases) had a higher response rate to trametinib (50.0% vs. 8.3%; Barnard’s P = 0.0004; test for interaction P = 0.054), but KRAS/BRAF/NRAS status was not predictive of prolonged PFS (test for interaction P = 0.719). KRAS amplification (n = 5 without KRAS/NRAS/BRAF mutation) and mutation of MAPK-associated genes (n = 25 without KRAS/NRAS/BRAF mutation or KRAS copy number gain) expanded the number of cases with identifiable MAPK defects to 55.2%, but consideration of these events did not improve the discrimination of trametinib responders. Chr1p loss (49% of cases) was associated with lower pERK expression (P = 0.021). Conclusions: This exploratory analysis suggests that pERK expression and mutation of KRAS/BRAF/NRAS are candidate biomarkers of improved PFS and response to trametinib, respectively.

Pertuzumab Plus Trastuzumab in Patients With Endometrial Cancer With ERBB2/3 Amplification, Overexpression, or Mutation: Results From the TAPUR Study

PURPOSE The TAPUR Study is a pragmatic basket trial evaluating antitumor activity of commercially available targeted agents in patients with advanced cancers harboring potentially actionable genomic alterations. Data from a cohort of patients with endometrial cancer (EC) with ERBB2 or ERBB3 (ERBB2/3) amplification, overexpression, or mutation treated with pertuzumab plus trastuzumab (P + T) are reported. METHODS Eligible patients had advanced EC, no standard treatment options, measurable disease (RECIST v1.1), Eastern Cooperative Oncology Group performance status 0-2, adequate organ function, and tumors with ERBB2/3 amplification, overexpression, or mutation. Simon's two-stage design was used with a primary end point of disease control (DC), defined as objective response (OR) or stable disease (SD) of at least 16 weeks (SD16+) duration. Secondary end points include safety, duration of response, duration of SD, progression-free survival (PFS), and overall survival (OS). RESULTS Twenty-eight patients were enrolled from March 2017 to November 2019; all patients were evaluable for efficacy and toxicity. Seventeen patients had tumors with ERBB2/3 amplification and/or overexpression, eight with both ERBB2 amplification and ERBB2/3 mutations, and three with only ERBB2 mutations. Ten patients had DC (two partial response and eight SD16+); all 10 had ERBB2 amplification, and 6 of the 10 patients with DC had >1 ERBB2/3 alteration. DC and OR rates were 37% (95% CI, 21 to 50) and 7% (95% CI, 1 to 24), respectively; the median PFS and median OS were 16 weeks (95% CI, 10-28) and 61 weeks (95% CI, 24-105), respectively. One patient experienced a grade 3 serious adverse event (muscle weakness) at least possibly related to P + T. CONCLUSION P + T has antitumor activity in heavily pretreated patients with EC with ERBB2 amplification and warrants additional study.

Comparing Durvalumab, Olaparib, and Cediranib Monotherapy, Combination Therapy, or Chemotherapy in Patients with Platinum-Resistant Ovarian Cancer with Prior Bevacizumab: The Phase II NRG-GY023 Trial

Abstract Purpose: We assessed the efficacy of anti–PD-L1 durvalumab in combination with olaparib and cediranib (DOC), compared with the standard-of-care chemotherapy (SOC) in patients with platinum-resistant ovarian cancer (PROC), who had prior bevacizumab. Patients and Methods: NRG-GY023 was the first randomized four-arm superiority phase II trial enrolling patients with high-grade serous/endometrioid or clear-cell PROC with prior bevacizumab exposure. Patients were randomized 1:2:2:2 to SOC (weekly paclitaxel, topotecan, or pegylated liposomal doxorubicin), DOC, durvalumab + cediranib (DC), or olaparib + cediranib (OC). The primary endpoint was progression-free survival (PFS). The secondary endpoints included overall survival, overall response rate, and safety. The design had 80% power to detect an HR of 0.5 using a one-sided, α = 0.1-level test for each comparison with the SOC with a preplanned interim analysis. Experimental arms with HR estimates (vs. SOC) >0.87 could be discontinued. Results: A total of 153 patients were enrolled between April 4, 2021, and February 1, 2023. Accrual was permanently closed on February 1, 2023, due to futility. With a data cutoff of September 9, 2024, the median PFS was 3.4, 2.9, 2.5, and 2.8 months, and median overall survival was 7.5, 8.3, 5.7, and 10.2 months for SOC, DOC, DC, and OC, respectively. The overall response rate was 4.3% [95% confidence interval (CI), 0.00–0.19], 15.9% (95% CI, 0.07–0.29), 11.9% (95% CI, 0.05–0.24), and 9.1% (95% CI, 0.03–0.20) for SOC, DOC, DC, and OC, respectively. Compared with SOC, the PFS HR estimates were 1.003 (95% CI, 0.56–1.80), 1.108 (95% CI, 0.63–1.96), and 1.021 (95% CI, 0.57–1.82) for DOC, DC, and OC, respectively. No new safety signals were observed. Conclusions: In patients with PROC with prior bevacizumab, all experimental arms failed to reach the primary objective of improving PFS compared with SOC.